ChatGPT Context Window Meter by Expsy

ChatGPT Context Window Meter adds a small in-page meter to chatgpt.com and chat.openai.com.

It estimates how much of the current conversation context window is being used based on the visible conversation text and the current draft message. The add-on is intended to help decide when a thread is getting crowded and when it may be better to start a new chat.

Features:
- Estimated context usage percentage
- Linear meter in full view
- Minimized circular meter mode
- Adjustable assumed context window size
- Adjustable reply buffer
- Runs entirely in the page as a lightweight content script

Important note:
This add-on does not use any private OpenAI API or hidden token counter. The displayed value is an estimate based on visible page content and simple token heuristics, so it should be treated as guidance rather than an official token count.